An assessment of auditory function of "normal" (healthy aging) subjects is being obtained through an Institute on Aging protocol investigating regional brain metabolism. Subjects are given audiologic assessment test batteries to develop a profile of risk factors for presbycusis. These include measures of pure tone and speech thresholds, supra-threshold speech recognition, special tests of auditory function, tympanometry, acoustic reflexes and auditory brain stem response. Aging changes are assessed by serial evaluations. Increasing loss of high-frequency hearing is the predominant finding and is consistent with other reports in the literature.